1. Field of the Invention
The present invention relates to a plasma display panel, and more particularly to a three electrodes face discharge type color plasma display panel in which three electrodes forming a discharge cell are arranged to generate an address discharge and a face sustaining discharge in a discharge space of the discharge cell.
2. Description of the Prior Art
Generally, a plasma display panel (hereinafter simply referred to as PDP) is a planer display panel which makes a discharge phenomenon by using a mixed penning gas. That is, the PDP generates a luminescence by discharging gases based on Helium (He) or Neon (Ne) having a relatively high atmosphere pressure (above 100 Torr.) between electrodes which are closely arranged to each other and are coated with a dielectric substance.
The mixed penning gas mainly consists of Ne+Xe or Ne+He+Xe. The reason for using the mixed gas is that the mixed gas has a lower discharge start voltage as compare with that of a pure gas. The discharge start voltage varies according to sorts of gases, a pressure of the penning gas and a structure or shape of the panel.
The above PDP has following advantages as compare with other display devices.
First of all, the PDP can be manufactured as a large size because it can variously take the address lines and the scanning lines. In addition, the PDP can adopt a multiplex technique so that the driving circuits thereof can be reduced. Further, the PDP has a longer life span of 50,000 hours than a cathode ray tube (CRT) which has a life span of 20,000 hours.
In addition, the PDP has a simple construction and is adapted to mass production since it has no fragile parts except for a glass. The PDP has a non-linear shape, so it has a high quality resolution of 100 line/inch. Since the gas having a refractive index of "1" is discharged in the PDP, a light is not extinguished while being reflected in the PDP and an external light cannot be reflected or scattered by indicating materials. In addition, unlike other flat panels, the PDP is sealed by the glass in the atmosphere above 400.degree. C. so that the PDP can be operated even when it is subjected to a high humidity or even when an active gas exists.
The PDP is divided into an AC type PDP and a DC type PDP according to a pattern of a driving voltage applied to the discharge cell. In the AC type PDP driven by a volts alternating current, the electrode is coated with an dielectric substance of a glass. On the other hand, in the DC type PDP, the electrode is not coated with the dielectric substance and a discharge current is generated when a discharge voltage is applied to the electrode.
FIG. 1 is a exploded perspective view for showing a conventional three electrode surface discharge type plasma display panel, FIG. 2 is a structural view of a whole electrode for showing a conventional three electrode surface discharge type plasma display panel having a resolution of 853.times.480, FIG. 3 is a cross-sectional view of a cell R.sub.ij (i is a column and j is a row) of a conventional three electrodes surface discharge type plasma display panel taken along line A.sub.1 -A.sub.2 of FIG. 2, FIG. 4 is a cross-sectional view of a cell R.sub.ij (i is a column and j is a row) of a conventional three electrodes surface discharge type plasma display panel taken along line B.sub.1 -B.sub.2 of FIG. 2.
Referring to FIG. 1, the conventional three electrodes face discharge type plasma display panel has a front glass substrate 10, a back glass substrate 20, a plurality of partition walls 30, a plurality of scaninig and sustaining electrode lines Y, a plurality of common sustaining electrode lines X, a dielectric layer 11, a magnesium oxide (MgO) protection film 12, a plurality of address electrode lines 15, and R, G and B fluorescent layers 21a, 21b and 21c.
The front glass substrate 10 and the back glass substrate 20 are parallely arranged at a predetermined interval. The plurality of partition walls 30 are arranged between the front glass substrate 10 and the back glass substrate 20 at a predetermined interval to form a plurality of discharge spaces.
The scanning and sustaining electrode lines Y are arranged at a predetermined interval on the front grass substrate 10 facing the back glass substrate 20 in a direction perpendicular to partition walls 30. The plurality of common sustaining electrode lines X and the scanning and sustaining electrode lines Y are arranged in pairs and generate a sustaining discharge in the discharge spaces.
The dielectric layer 11 is formed on the plurality of common sustaining electrode lines X and the scanning and sustaining electrode lines Y so as to limit a discharge current and so as to generate a wall charge easily. The MgO protection film 12 is formed on the dielectric layer 11 in order to protect the common sustaining electrode lines X and the scaning and sustaining electrode lines Y. Also, the MgO protection film prevents the dielectric layer 11 from being eroded and corroded.
The plurality of address electrode lines 15 are parallely formed with the partition walls 30 on the back glass substrate 20 and generate the address discharge in the discharge spaces together with the sustaining electrode lines Y.
The R, G and B fluorescence layers 21a, 21b and 21c are respectively formed on the address electrode lines 15. When the sustaining discharge is generated by the common sustaining electrode lines X and the scanning and sustaining electrode lines Y, R, G and B visible lights are emitted from the R, G and B fluorescent layers 21a, 21b and 21c as the R, G and B fluorescent layer 21a, 21b, 21c are excited by vacuum ultreviolet rays.
Referring to FIG. 2, four hundred eighty scanning and sustaining electrode lines Y1-Y480 and four hundred eighty common sustaining electrode lines X1-X480 are alternately arranged one by one on the same plane (on the front glass substrate). Two thousands five hundred fifty nine (853.times.3 (R, G and B)) address electrode lines R1, G1, B1, . . . , R853, G853 and B853 are arranged on the back glass substrate 20 such that they can be perpendicular to the scanning and sustaining electrode lines Y1-Y480 and the common sustaining electrode lines X1-X480 at a predetermined interval therebetween. R, G and B cells 50, 51 and 52 are alternately formed at each intersection of the scanning and sustaining electrode lines Y1-Y480 and the common sustaining electrode lines X1-X480 and address electrode lines R1, G1, B1, . . . , R853, G853 and B853. Accordingly, 1,228,320 (480.times.853.times.3) R, G and B cells have a matrix shape.
Referring to FIGS. 3 and 4, a scanning and sustaining line Yi and a common sustaining electrode line Xi are parallely formed on the front glass substrate 10 facing the back glass substrate 20. A dielectric layer 11 having a predetermined thickness is formed on the scanning and sustaining electrode line Yi and the common sustaining electrode line Xi. The MgO protection film 12 is formed on the dielectric layer 11.
In addition, a first partition wall 30a and a second partition wall 30b are perpendicularly arranged with the scanning and sustaining electrode line Yi between the front glass substrate 10 and the back glass substrate 20 in order to form a discharge space and prevent colors of cells from mixing with each other. An address electrode line Rj is formed on the back blass substrate 20 formed between the first partition wall 30a and the second partition wall 30b. The R fluorescent layer 21a is formed on the address electrode line Rj. Inside of the discharge space is filled with a penning mixed gas.
The above-mentioned R cell operates as follows.
The address discharge is generated between the scanning and sustaining electrode line Yi and the address electrode line Rj and charge particles are generated within the discharge space by the address discharge. By the charge particles, optimum wall charges are generated on a surface of each of the electrode lines Yi, Rj. When the optimum wall charges are generated, the sustaining discharge is continuously generated between the scanning and sustaining electrode line Yi and the common sustaining electrode line Xi. Therefore, R vacuum ultraviolet rays are generated by the sustaining discharge so that R fluorescence layer 21a is excited by the vacuum ultraviolet rays, thereby generating R visible rays. In this manner, if the R visible rays generated in the discharge space of the R cell are emitted to an exterior through the front grass substrate 10, the luminescence of the R cell can be recognized.
Since a discharge area in the discharge space is formed between the scanning and sustaining electrode line Yi and the common sustaining electrode line Xi which are formed on the front glass substrate 10 in parallel to each other, it is called "face discharge type PDP".
Although the R cell is described as an example above, internal structures of the G cell and the B cell are almost identical to that of the R cell, except for the G cell and the B cell respectively have the G fluorescence layer 21b and the B fluorescence layer 21c instead of the R fluorescence layer 21a.
However, the conventional three electrodes face discharge type plasma display panel has so many scanning and sustaining electrode lines and common sustaining electrode lines on the front glass substrate that the visible light, which is generated in the discharge space and passes through the front glass substrate, is interrupted by the scanning and sustaining electrode lines and the common sustaining electrode lines. As a result, an amount of the visible light passing through the front glass substrate is reduced so that a brightness of the cell as well as an image can be deteriorated.
In addition, in order to allow the scanning and sustaining electrode lines and the common sustaining electrode lines to generate the face discharge with one another, the discharge area in the discharge space is horizontally formed in the conventional three electrodes face discharge type PDP. For this reason, there occurs a discharge interference between adjacent cells.
Furthermore, in the conventional three electrodes face discharge type plasma display panel, a luminescence efficiency of the R fluorescence is higher than that of the B fluorescence, and a luminescence efficiency of the G fluorescence is higher than that of the fluorescence. Accordingly, if the R, G, and B cells are operated in the same condition with the same structure, the brightness thereof will be presented as the G cell&gt;the R cell&gt;the B cell. Therefore, a white balance is unstable, that is, when a white color is projected, a white-green color may be presented.